Upgrade your manual brake car to a 9 in. slimline power booster and a 1 in. dual bore master cylinder with our quick install hydraulic brake booster kit. This 1971-73 Mustang power booster kit allows you to upgrade your factory manual brake car in no time. In this 1971-73 Mustang hydraulic brake booster kit you receive the brake lines necessary to route from the new master cylinder to your factory distribution block. With this 1971-73 Mustang power booster kit you will also receive a pushrod adapter for your factory brake pedal. A great hydraulic brake booster kit with a factory look and easy installation! Designed for 4 wheel drum brake applications.